High aspect ratio all sige capacitively coupled mems devices

A method of forming a MEMS device, comprising:

• forming a first sacrificial layer on a substrate;
• forming a first electrode layer on the first sacrificial layer;
• forming a second sacrificial layer on the first electrode layer;
• forming a recess in the first electrode layer having sidewalls that correspond to a surface of at least one suspended electrode;
• forming a third sacrificial layer having a first width adjacent the sidewalls;
• forming a second electrode layer adjacent the third sacrificial layer that corresponds to a second electrode;
• and
• removing portions of the first sacrificial layer, the second sacrificial layer, and the third sacrificial layer to form the at least one suspended electrode separated from the second electrode by a second width that corresponds to the first width of the third sacrificial layer.

A method of forming capacitively coupled electrodes separated by an opening, the method comprising:

• forming a recess in a first electrode layer, the recess having sidewalls that correspond to a first surface of at least one first electrode;
• forming a sacrificial layer overlying the first electrode layer including on the sidewalls of the recess, the sacrificial layer having a first width that corresponds to a second width of the opening;
• forming a second electrode layer overlying the sacrificial layer that corresponds to the second electrode;
• removing portions of the sacrificial layer to form the opening between the at least one first electrode and the second electrode.